The present invention relates to endoscopes for treating strictures in the urinary passage, of the kind comprising an outer barrel which is open at the bottom for its entire length, with the width of the opening at least corresponding to the diameter of an implant catheter to be inserted in the bladder, a telescope which can be inserted in the outer barrel, and a blade movable in the distal direction for slitting the stricture. Hereinafter such endoscopes will be referred to as "of the kind described".
Strictures in the urinary passage are slit open by an endoscopic operation, while under observation, by means of an endoscope comprising an outer barrel, an examination barrel and an operating barrel, and to prevent a fresh constriction from developing during healing, an implant catheter of a known kind is inserted through the urinary passage and into the bladder. To allow this pliable implant or balloon catheter to be inserted without difficulty, use is made of an endoscope having an outer barrel, as described for example in German Gebrauchsmuster No. 7,339,606, which is open on the underside for its entire length across a width corresponding to the diameter of the catheter. In this way the outer barrel can be used to insert the catheter an can then be withdrawn again while leaving the catheter in place in the urinary passage. The catheter, which remains in place until the stricture has healed, provides an avenue for urine to flow through but in the region concerned there is heavy scarring in the urinary passage and the opening in it is not round. The danger therefore exists that because of the scarring the passage will become smaller again in the course of time and the operation will have to be repeated.
It is therefore an object of the invention to create an opening of circular cross-section in the urinary passage after a stricture in the passage has been slit open and thus to avoid repeated operations as far as possible.